The present invention relates generally to controlling printed products, for example signatures.
In a folder of a printing press, a web of paper often is folded and then cut, for example using a first set of cutting cylinders to make a first cut, and then a second set of cutting cylinders further downstream to complete the cut to form signatures. Tapes often are used to support the signatures on both sides while the second set of cutting cylinders is finishing the but between the tapes. A delivery device, for example deceleration drum, then can grip the front edge of the signatures through the tapes so as to transfer the signatures to the deceleration drum. A set of grippers that extends through the tapes is typically provided in the delivery device.
The components that grip and transport the printed signatures are generally desired to be as wide as possible to minimize marking an damage to the products as well as to support a variety of product widths.
These gripper components sweep between the tapes. The tapes are supported on pulleys which are supported by lever arms. However, existing lever arms typically are much wider than the pulleys, and thus reduce the space for the grippers that pass between the tapes.
FIG. 1 shows a prior art device with a tape transport mechanism 2 and a signature diverter 4. Diverter flippers 18 of the diverter 4, supported on a pivot center 16, pass between pulleys 15, 115 which support tapes 14, 214 on the left side of FIG. 1. Other tapes are not shown for clarity. The lever arms 12 that support the pulleys 15, 115 are supported on a rod 10.
As shown in FIG. 2A for another prior art device, an adjustable lever arm 12 having an air cylinder for extending the arm length has a side support 11 for pulley 15 which causes the width 118 of the lever arm and pulley combination to be much larger than a tape width 114, for example 2.21 times as large. FIG. 2B shows a side view of the adjustable lever arm 12, while FIG. 2C shows details of the pulley 15 through section Axe2x80x94A in FIG. 2B. FIG. 2D shows a perspective view of the adjustable lever arm 12.
The large ratio between width 118 and width 114 reduces the space S between the lever arms supporting tapes similar to tapes 14, 214 (See FIG. 1) permissible for the parts 218 of the diverter flippers 18 that extend between the tapes.
An object of the present invention is to provide a reduced ratio of the pulley and lever arm width with respect to the tape width.
A further alternate or additional object of the invention is to be able to increase the effective gripper or diverter width.
Another alternate or additional object of the present invention is to provide improved gripping and handling of printed products.
The present invention thus provides a tape transport system for printed products comprising a first tape, a pulley supporting the tape, and a lever arm supporting the pulley, the lever arm including a first side rail and a second side rail, the pulley supported rotatably between the first and second side rails.
xe2x80x9cRailxe2x80x9d as defined herein is an elongated thin piece of material.
Preferably a plurality of tapes are provided, each tape supported by a pulley and lever arm with two side rails.
The side rails preferably are thin sheets, for example made of steel.
The present invention also provides a lever support arm for a tape pulley of a folder in a printing press comprising a first side sheet, a second side sheet and a pulley supported between the first side sheet and the second side sheet.
The present invention also provides a method for transporting printed products comprising transporting signatures using a first tape, and passing the first tape over a pulley, the pulley being supported on a lever arm supporting the pulley, the lever arm including a first side rail and a second side rail, the pulley supported rotatably between the two side rails.
The present invention also provide a folder comprising:
a tape transport device having a first tape and a second tape, a first pulley supporting the first tape and a second pulley supporting the second tape, a first lever arm supporting the first pulley, the first lever arm including a first side rail and a second side rail, the first pulley supported rotatably between the first and second side rails; and
a printed product transfer device including at least one component passable between the first tape and the second tape.
Preferably, the transfer device is a deceleration drum and the component a gripper.
Preferably, the ratio of a combined width of the first pulley and the first side rail and second side rail at the pulley to that of the tape is less than 2, and most preferably less than 1.2.
Preferably, the second lever arm includes two side rails, the second pulley being supported between the two side rails.